Statistics
Robert Short
Cardiovascular Event Predictors

Diabetes claims many lives through its effects on the kidney and heart, and contributes substantially to cardiovascular disease generally. The evaluation of clinical psych-social intervention studies is important in understanding the most efficient and effective ways of disseminating relevant information about the disease, how the disease can be treated, and for teaching patients ways of coping with the disease. Another equally important area of interest has to do with physiological risk factors of the disease process. The aim of our work is to determine whether there are elevated risks of cardiovascular mortality and clinical events associated with high levels of albumin in the urine and high levels of serum uric acid in the blood of patients with coronary artery disease. Two published papers set the stage for our current work. The first showed that microalbuminuria predicts

the presence of coronary artery disease (CAD) in patients referred for elective angiography (Am J Kidney Dis 1999; 34: 918-925). We found that albumin in the urine correlated with CAD severity and was independent of traditional risk factors. The second article showed that serum uric acid levels also correlate with CAD severity, particularly in women (Am J Card 2001; 87: 1411-1414). We then followed these same cardiac patients (N = 316) for five years and recorded major cardiovascular events: mortality, myocardial infarction, stroke, amputations, and renal failure (dialysis or transplantation). Using a Cox proportional hazards model in an event analysis, it was found that a patient’s prior severity of disease, high cholesterol levels, and high levels of uric acid in the blood during the baseline period predicted the later major events. Indeed, uric acid levels greater than 5.5 mg/dl increases the relative risk of an event almost four times (Figure 1). Thus a subtle increased uric acid contributed to predicting increased cardiovascular risk over five years after controlling for CAD severity and other risk factors at baseline. These findings have important implications for early identification and possibly prevention of future major cardiovascular events. We plan to expand our work by testing similar statistical models in the general population. Other related areas of investigation involve examining the effects of amino acids and glucagons on renal hemodynamics in type 1 diabetes.

Contact Information
Dr. Robert Short, Ph.D.
Assistant Director
Washington Institute for Mental Illness: Research and Training

WSU Spokane, HSB 280K
PO Box 1495
Spokane, WA 99210-1495

Telephone: 509-358-7617
E-mail: rshort@wsu.edu